We determined the synthesis conditions for successive ionic layer deposition of the Sn-16(OH)(x)PW19Oy-nH(2)O nanolayers on silica surfaces. The synthesized layers were characterized using UV-Vis and FTIR absorption spectroscopies, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). On heating the as-synthesized layers to 200-500 degreesC in air, incorporated water evaporate, while M-OH groups are condensed and concentration of the W-O-W and W-O-Sn bonds increase. The layers have amorphous agglomerate-like structure. The agglomerate size is from 20 to 100 nm. Upon heating to 600 degreesC, the size insignificantly increases, the agglomerate form being practically unchanged. The data obtained allow conclusion that the layers present a hybrid compound consisting of fragments of isopoly-(SnxOyHz) and heteropoly-(HxPWyOz) compounds. (C) 2003 Elsevier B.V. All rights reserved.